Inheritance using annotations

some one · **Joined:** Thu Jan 29, 2009 8:49 pm **Posts:** 5

Hello,

I am trying to do something very simple. I have different types of contact information like emails, addresses, phones etc stored in one table with a discriminator column.

I have a parent class called ContactInfo

Code:

@Entity
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="CT_CODE",  discriminatorType = DiscriminatorType.STRING)
@Table(name= "MX_ADDRESS")
public class ContactInfo extends Serializable
{
...
}

Each of the contact types have their own classes for eg

Code:

@Entity
@DiscriminatorValue("addr")
public class Address extends ContactInfo 
{
 ...
@ManyToOne
@JoinColumn(name="MAST_ID")
private Master owner;
}

@Entity
@DiscriminatorValue("fax")
public class Fax extends ContactInfo 
{
...
@ManyToOne
@JoinColumn(name="MAST_ID")
private Master owner;
}

Now when i try to get only the addresses it returns me back all the addresses

Code:

Session session = getHibernateTemplate().getSessionFactory()
             .getCurrentSession();
Criteria criteria = session.createCriteria(Address.class);
criteria.list();

All the contact information belong to a person.

Code:

@Entity
@Table(name= "MX_MASTER")
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="MAST_MEMEX_INDORG", discriminatorType= DiscriminatorType.STRING)
public class Master extends Serializable
{
...
    @OneToMany(mappedBy="owner")
    @Cascade({CascadeType.ALL, CascadeType.DELETE_ORPHAN})
    protected Set<Address> addresses = new TreeSet<Address>();
}

@Entity
@DiscriminatorValue("I")
public class Individual extends Master 
{
...
}

But now when i tried to go through the member it returns me back all the contact info even if i am just looking for addresses

Code:

Master o = (Master ) getHibernateTemplate().get(Master.class, new Long(714));
o.getAddresses().size();

I am not sure why is the discriminator column in Address not being used. Can any one help???

~s.

mmerder · **Posted:** Tue Feb 03, 2009 1:18 pm

The problem is, that you join on the same column. You can fix it if you use

Code:

@OneToMany(mappedBy="owner")
    @Cascade({CascadeType.ALL, CascadeType.DELETE_ORPHAN})
    @Where(clause="CT_CODE='addr'") 
    protected Set<Address> addresses = new TreeSet<Address>(); 